BREEAM excellence rating for the 400,000 sq ft mixed-use development in London.

Central St Giles is the Renzo Piano-designed, former Ministry of Defence building near Tottenham Court Road and New Oxford Street, London. The 400,000 sq ft development has been transformed from an inaccessible building to a mixed-use scheme that is let to companies such as WPP, Google and NBCUniversal.

The buildings, which were completed in 2010 and achieved BREEAM 'Excellent', have the most obvious feature of multi-coloured façades, covered in 134,000 glazed tiles in shades of green, orange, lime and yellow. In sustainability terms, these are designed to offer an efficient thermal façade. Sustainability measures were, of course, part of the planning stipulations and include: four levels of landscaped green and brown roofs (some accessible to tenants); 60 per cent collection and reuse of rainwater - for irrigation and toilet flushing; 80 per cent of the heating from biomass boilers - one of the first city centre projects with a site-wide biomass heating system; HVAC by DeLclima, one of the foremost suppliers of HVAC systems in terms of sustainability; 100 per cent of the cooling tower water going into toilet flushing (grey water); 90 per cent of demolition materials recycled, and 15 per cent recycled materials used in construction. The 3 FOCS-W high-efficiency water-cooled DeLclima chillers, providing over 1800kW cooling capacity, form an integral part of the energy provision and serve the buildings fan coil units, AHU's and chilled beams. These units ensure perfect comfort for occupants, with greatly reduced CO2 emissions and low running costs.The HVAC capability complies with the consultant's design intent and also ensures accelerated return on initial investment, which was also a key stipulation.